Type

Type may refer to:

In philosophy:

In theology:

In mathematics:

In computing:

In sociology:

Other:

Type (biology)

In biology, a type is one particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralize the defining features of that particular taxon. In older usage (pre-1900 in botany), a type was a taxon rather than a specimen.

A taxon is a scientifically named grouping of organisms with other like organisms, a set that includes some organisms and excludes others, based on a detailed published description (for example a species description) and on the provision of type material, which is usually available to scientists for examination in a major museum research collection, or similar institution.

Type specimen

According to a precise set of rules laid down in the International Code of Zoological Nomenclature (ICZN) and the International Code of Nomenclature for algae, fungi, and plants (ICN), the scientific name of every taxon is almost always based on one particular specimen, or in some cases specimens. Types are of great significance to biologists, especially to taxonomists. Types are usually physical specimens that are kept in a museum or herbarium research collection, but failing that, an image of an individual of that taxon has sometimes been designated as a type. Describing species and appointing type specimens is part of scientific nomenclature and alpha taxonomy.

Type (designation)

The word Type followed by a number is a common way to name a weapon or product in a production series, similar in meaning to "Mark". "Type" was used extensively by the Japanese and Chinese militaries beginning in the 1920s, and is still in current use by the militaries of both nations. The United Kingdom uses a type number system for much of their military equipment. Many other nations use the word "Type" to designate products in a series.

Japan

The Imperial Japanese Navy (IJN) began using the Type-Number System in 1921 to designate aircraft accepted for production. The numbers used after the word "Type" were based on the number of years that the Emperor Taishō had reigned. Since his reign began in 1912, an aircraft ordered into production in 1921 would have been called "Type 10", the tenth year of the emperor's reign. At the end of 1926, the emperor died, leaving his son Hirohito as the Emperor Shōwa, and the numbering system was reset to mark the new emperor's reign.

In 1929, the government of Japan adopted a new system based on the imperial year. Aircraft ordered for production from 1929 onward were assigned the last two digits of the year marking the continuity of Japanese emperors. 1929 was the 2589th imperial year, so aircraft ordered that year were designated "Type 89". 1940 was the 2600th year, and the IJN numbering system was reset to single digits. New aircraft were designated 0 (zero). The well-known Mitsubishi A6M Zero was ordered into production in 1940 as the IJN "Type 0 Carrier Fighter" (Rei shiki Kanjō sentōki, 零式艦上戦闘機), and was popularly called the "Zero" because of its type.